HEXACRINIDiE. 789 



in the first row, which is followed by a smaller one. The anal interraclius, 

 which is much the widest, has one plate in the two 2}roximal rows, followed 

 by small pieces forming a little protuberance around the anus. Orals repre- 

 sented by a single piece, from the sides of which the covering plates of the 

 ambulacra pass out to the arms ; the plate is highly convex or nodose, and 

 as large as the five orals in other species. Ambulacra projecting, the cover- 

 ing plates consisting of two rows of small pieces, which are alternately 

 arranged ; they bifurcate on a rather large axillary, and the two branches 

 are separated by a large interdistichal. 



Horizon and Locality. — Upper part of St. Louis group ; Tateville, 

 Pulaski Co., Ky. 



Types in the collection of Wachsmuth and Springer. 



Remarks. — This species is remarkable for having but a single oral plate ; 

 the other four orals are either undeveloped, or, more probably, were resorbed 

 in the growing crinoid. Another peculiarity of this species is the absence of 

 spines, and the presence of regular covering pieces in the disk. 



Meek and Worthen's Dichoainus constrictus may possibly be identical 

 with this species, but as only the baSals and radials are known no satis- 

 factory comparison can be made. 



Talarocrinus subglobosus w. and Sp. (nov. spec). 

 Plate LXXIX. Figs, la, h. 



A small species. Calyx proportionally shorter than in T. dccornis, and 

 subglobose instead of ovate ; the interradial spaces depressed at the arm 

 regions ; plates of the dorsal cup rounded and a little convex : suture lines 

 somewhat grooved. 



Basal cup small and quite shallow ; widest at right angles to the suture 

 line; the lower face slightly excavated. Radials about as wide as long, 

 rapidly spreading from the base upward, tumid, and a little inflected at the 

 upper part ; radial facets broadly excavated, and the limbs slightly truncated 

 for the reception of the interbrachials. Anal plate larger than the radials 

 and considerably widest across the middle. Costals quite large for the genus, 

 filling almost the entire width of the facets in which they rest. Distichals 

 2X2, short, those of the first I'ange slightly touching the radials, and all, 

 together with the costals, facing outward. Arms four to the ray, free above 

 the distichals. Ventral disk subpyramidal, a little shorter than the dorsal 



